Differentiation landscape of swimming ability of Tuzoia species from Wuliuan,Cambrian revealed by computational fluid dynamics
Tuzoia is one of the most common and globally distributed Cambrian bivalved arthropods.However,the morphology of their rarely and incompletely preserved soft-parts can hardly be utilized to evaluate their swimming and migration abilities.Computational fluid dynamics(CFD)offers quantitative data for inferring the movement patterns of fossilized animals based on the morphology of their often well-preserved exoskeletons.In this paper,Tuzoia retifera and T.canadensis from the Burgess shale are simulated using CFD in benthic and pelagic environ-ments.The differences in fluid performance and vertical flexibility of these two species are compared.Fluid simu-lation results indicate that T.retifera is subject to less drag force and greater lift force than T.canadensis under the same speed.The results indicate that T.retifera potentially has a faster swimming speed and better vertical mi-gration ability than T.canadensis does.Tuzoia canadensis is probably a benthic species,while T.retifera may oc-cupy wider habitat and has a pelagic swimming lifestyle.We suggest that niche partititoning within a genus oc-curred as early as the Wuliuan,Cambrian.